Wow, this went to places I did NOT expect. XD

@toxicitzi  
I admit, Tirek was cooler, but Sombra had some interesting differences, and the subtleness, and mystery of him, I felt was a nice change of pace from the usual hammy “Mwahahaha” dialogue heavy villains.
 
In fact, looking back at Chrysalis’s first episode, she wasn’t very fleshed out either, and all we knew was she was the Changeling queen, and her motivation was just to take over, and steal love for sustainance. Discord was even a bit ambiguous as to whether he was genuinely evil, or just a cosmic pranker with no real understanding of morality. (Kinda like Q, the character he was loosely based on.) Before his second appearance, and his reformation starting, many fans actually portrayed him as extremely evil, like in fanfics, and stuff like “Woonastuck.” That all now feels strange as looking back, Discord wasn’t evil per-say, but not a good guy either.  
I like how even after his reformation, his behavior is still not always the best, and he still gets to be Discord. Like how he was bugging Twilight throughout the Season 7 opener, you can’t tell if he’s actually being naive, or just trying to mess with Twi’ a bit. (Perhaps even a bit of both.)

@Beau Skunky  
I kind of inferred as much, since you said it as though it were their fault for it happening. on that s5 note, I get it, I can’t blame them for not doing anything in s5 with him, it was very brief.
 
I guess what I mean is, Tirek is the version of Sombra done well, intimidating and blatantly evil, but I guess I too had a few expectations of Sombra, but you know, he’s just that big bad unicorn that enslaves ponies to dig up crystals for him. For all I know, maybe his goal was supposed to be his pursuit of fine arts and he had something in mind to do with the crystals he was having those ponies dig up.
 
I’ll admit this though, the one fun thing about Sombra are all the jokes that came with him.

@toxicitzi  
I’m not blaming fans for why IDW took him that direction, I don’t know how you came to that conclusion about my post.
 
Though, personally, sense they actually killed him off on-screen, (which is partially why I assume they didn’t flesh him out too much, so fans wouldn’t be too attached to him) I’d rather they keep him that way as reviving him would make his demise cheap. I liked his his cameo role in the Season 5 finale though.

@Beau Skunky  
you’re not blaming that backstory on people with legitimate criticisms about the show Sombra? because, I don’t think that’s what the criticism meant and how IDW took it, well, let’s just say it’s become typical of them to do so.
 
but enough about that, the point is, no one really cares about that anymore and trying to somehow appease that criticism, that boat has long since set sail.. If two appearances from Sombra couldn’t bother explaining anything at all about him, the same kind of information of a character as we know about Discord/Tirek/Chrysalis/Starlight (pre-redemption), what are even the odds the show will do anything of the sort with him?

Discord is the only one with proper reformation. And he embraces his new life not mopping around about his past like Luna or Starlight. While he enjoyed the chaos, he realised that being alone sucked and now he hopefull about his future with Fluttershy.

@Ledvi  
True, it is getting over done.
 
I’m not an IDW comic hater, but I didn’t like how they turned King Sombra into another “watered-down villain.”  
Many fans complained that Sombra was a “typical for the evulz villain,” and thought he was boring for not having a detailed backstory, or hardly any dialogue, but frankly I think I preferred him as a foreboding, mysterious, badass, and genre-savvy villain (judging by his traps & tricks) over what the comics did to him.
 
As you said, tragic sympathetic villains are getting overdone.

My reason is because he’s not a tragic villain. I swear you nearly see them everywhere.

To be fair, he is part horse.